Device for indicating loss or use of gas from a container holding liquified gas



Sept. 16, 1958 w. L. KEEHN 2,851,985

DEVICE FOR INDICATING LOSS OR USE OF GAS FROM A CONTAINER HOLDING LIQUIFIED GAS Filed 001;. 2, 195a VINVENTOR. WARNER L. KEEHN ATTORNEYS United States Patent DEVICE FOR INDICATING LOSS OR USE OF GAS FROM A CONTAINER HOLDING LIQUIFIED GAS Warner L. Keehn, Santa Rosa, Calif.

Application October 2, 1956, Serial No. 613,477

6 Claims. (Cl. 116-114) a This invention relates to an indicating device adapted to be connected to the ordinary valved gas discharge conduit of a bottle or container holding liquified gas, and which device is operable under the pressure of gas passing out of said conduit and past the valve therein so as to give an indication that gas has been discharged from the container.

Heretofore the customary method of determining if there has been a leakage of gas from a container of liquified gas, such, for example, as CO or if any gas has been purposely or accidentally withdrawn from such tank, has been to weigh the container. The gas pressure in the container will remain substantially the same as long as there is liquified gas in the container, hence a pressure 7 gauge is of no value.

Apart from the fact that it involves considerable time and labor to weigh the liquified gas containers, there are many instances where scales are not readily available for weighing the containers, or where the containers are connected in piping installations that would require disconnecting the pipes and immobilizing the system in order to weigh the container. There is the constant occurrence of leakage from containers in storehouses, with the result that a user receives only a partially filled container, when such container should be completely filled when it reaches the user. There are a great many other places and instances where the safety of persons and property depends upon there being an'adequate supply of liquified gas on hand for emergency use, and if this supply has been depleted through discharge of gas from the container, either through leakage or intentional withdrawal, the, lives of many become imperiled.

One example of the vital importance of knowing 'whether or not a supply of liquified gas on hand in a piping system is illustrated in my copending application for United States Letters Patent, Serial No. 519,852, filed July 5, 1955, for Fluid Pressure Brake System, and in which system a supply of liquid CO provides an emergency supply of gas for operating the vehicle brakes in the event the compressed air is inadequate. It is not sufficient in such an instance to know that the full pressure is available for operating the brakes, since the pressure will exist when the liquified gas is virtually exhausted.

The main object of this invention is the provision of an indicating device that is adapted to be connected to the discharge conduit of a container for liquified gas, such as CO or oxygen, to positively show whether or not any gas has leaked from the container through the discharge conduit, and whether or not any gas has been discharged accidentally or purposely from the container through the discharge conduit.

Another object of the invention is the provision of a device adapted to give a clear indication of gas leakage or discharge, as above described, and which device may be a fixed installation in the discharge conduit and part of the conduit, and that may easily and quickly be reset after being actuated.

A still further object of the invention is the provision of a device of the above character that is economical to make and that is virtually infallible in operation. 7

An additional object of the invention is the provision of an indicating device in combination with a contain'er of liquified gas and in the discharge conduit from such container, that is adapted to be actuated by the'pressure of gas escaping or discharged from said container and through said conduit and past a valve in the latter, to indicate that a gas leakage or discharge of gas from the container has occurred.

Another object of the invention is the provision of an indicator that is quickly reset when desired and that is provided with a seal that is broken with each operation of the device where there has been a discharge of gas, and which seal is quickly replaced with a new one after the device is reset. The seal preferably functions to hold the indicator concealed and in a position ready for actuation, before the seal is broken.

Other objects and advantages will appear in the descrip tion and in the drawings.

In the drawings, Fig. 1 is a reduced size fragmentary side elevational view of the upper end of a conventional container for liquified gas, such as liquid CO or liquid oxygen showing the usual valve therein and showing the device of the present invention in position, but with the indicator concealed.

Fig. 2 is a view similar to that of Fig. 1, except that the indicator on the device of the present invention is exposed showing that gas has leaked from the container through the valve or that the valve has been accidentally or purposely actuated to discharge gas from the container.

Fig. 3 is an enlarged elevational view of the indicating device of this invention.

Fig. 4 is a vertical cross-sectional view taken through the device of Fig. 3.

. Fig. 5 is a vertical cross-sectional view similar to that of Fig. 4 except that the indicator has been actuated as indicated in Fig. 2.

Fig. 6 is a bottom plan view of the device of Fig. 3.

In detail, the conventional bottle or container for liquid CO or liquid oxygen or any liquified gas adapted to vaporize at atmospheric pressure and temperature is indicated at 1, said container usually being capable of withstanding high internal pressure and each of such containers usually has a manually actuatable valve 2 thereon provided with a discharge outlet 3 for discharge of gas that is within the upper end of the container above the liquid therein when the valve is actuated to open the same.

Usually the outlet is connected with a tube, hose, or other conduit for delivery of the gas to the desired point away from the container, and pressure gauges and pressure regulator valves may be in said conduit according to the work to be done. Where a pressure gauge is in said conduit, it normally will indicate when the liquid within the container is completely vaporized by showing a decrease in gas pressure, but normally there is no change that indicates how much liquified gas is in the container.

In the present invention, a body 5 is provided. The actual size of this body is preferably the same as the size shown in the drawings.

Said body, as illustrated herein, is formed with a straight elongated passageway 6 therein which passageway connects at one end with a reduced diameter passageway 7, coaxial therewith. This latter passageway extends through a threaded boss 8 on the body, and this threaded boss is adapted to receive and threadedly engage a pipe 9 that connects with the outlet 3 in valve 2. I

A duct 10 formed in said body communicates at'one end with a side of passageway 6 at a point that is spaced from the end of the passageway 7 a substantial distance.

This duet extends through an internally threaded boss 12 that may threadedly engage the threads on the end of a pipe 13. This pipe 13 may extend to any desired ppint and, if desired, may have a pressure, regulator and othergauges therein, as already mentioned, or where the gas isfrequently withdrawn from the container after the latter has been delivered and the device is no longer desired, the body 5 can quickly be removed. The pipe 9 serves the same function as pipe 13. Thus the present device in no way interferes with the usual manner of connecting the discharge conduit in any desired system, and it need not be disconnected from the container any more than valve 2, when the container 1 is stored, shipped, or otherwise held or installed in a system.

A piston 15 is closely fitted in passageway 6. This piston may be of neoprene, rubber or any other suitable material providing a gas tight fit with the walls oi the passageway.

The passageway 6 extends a substantial distance past the openingof duct '10 into the same, which distance is sufficient to enable the piston 15 to clear said opening upon movement of the piston in direction away from the passageway 7 under theinfiuence of gas entering said passageway through the pipe 9 leading from outlet 3.

A head 16 is secured against the side of body 5 through which the outer end of the passageway 6 opens, and said head is formed with an opening 17 that is of slightly smaller diameter than the diameter of the passageway 6. Screws 18 may secure the head 16 to body 5 with opening 17 coaxial with passageway 6. Thus the head becomes part of the body 5, but is removable therefrom. and it actsjas a stop to prevent the piston from moving completely out of passageway 6.

A stem 19 carries the piston 15 and projects axially therefrom and into the opening 17 when the piston is in the end of passageway 6 into which the passageway 7 opens, and is between said passageway 7 and the opening t duct 10 into passageway 6. This stem is preferably painted red so as to be clearly seen when it projects from the opening 17 and outwardly of body and head 16.

The head 16 is provided with a pair of apertured cars 21 that are in opposed relation extending outwardly of the head16 at opposite sides of the opening 17, but at the edges of said head. A wire 22 extends through said ears and across the opening 17 and the'outer end of the stem 19 and the free ends of said wire maybe held together over said outer end of stem 19 by a lead seal 23... Thus the wire 22 will hold the piston in position between the passageway 7 and the duct against accidental movement of the piston to a position over or past the duct 10 and against accidental movement of the stem 19 to a position projecting outwardly of the device. Until and unless the seal is broken, the stem 19 will be concealed within the body 5 which includes head 16.

In operation, a leakage of gas past the valve and into passageway 7 will build up pressure against the piston suflicient to break the seal, and to permit the gas to flow through passageway 6 and duct 10 .to the outlet pipe 13. The first intentional or accidental discharge of gas from the container 1 through actuation of valve 2 will also break the seal. In any of the above instances, the breakage of the seal will result in the piston moving past the duct 10 and to a position in which the stem 19 is exposed, thereby giving the user a clear indication that gas has been discharged from the container, and that it is no longer a completely filled tank.

This is invaluable information since the operator will then be aware that he cannot'thereatterrely upon there being a full container.

If the indicator is actuated after the container has been filled and is awaiting shipment to a user, the indication is clear that the valve is not tight, and the shipper has an opportunity to change the valve.

If at the time the container is delivered to 6 User,

the vindicatoruhas beenactuatfid so that .the .red ,stemis exposed, the user has a clear warning that the container no longer is completely filled, and he may refuse to accept the same, or he may require weighing the same to determine the actual loss that has occurred.

In many instances where the. gas supply is provided for use in emergencies, any such use usually requires the replacement of the container with one that is completely'filled, but in the event the user has purposely withdrawn a small amount of gas, the piston and stem may be reset and the seal replaced. In this latter instance, the device may be mainly used for the purpose of giving Warning of accidental leakage past the valve in intervals between use, rather than relying upon the device to give an indication of a completely filled tank.

The fact that the stem preferably extends downwardly provides a means for knowing if the seal has been securely fastened after 'a filling and before shipment." If theseal is not fastened, it' riiay be positioned to move accidentally to an exposed position. Thus the operator or user isgiven a chanceto discoverif the exposure has been du'e'to carelessness in not fastening the seal or to a leakage or discharge. Normally the friction between the piston 15 and the walls of the passageway is adequate to hold the piston at the inlet end of the passageway in the absence of gas entering the inlet.

I claim: 7 i

1. An indicating device adapted to provide part of a discharge conduit from a source of a fluid under pressure comprising: a body having a passageway therein. an inlet and an outlet opening into 'said passageway at spaced points therealong, a piston within said passageway movable therealong under the pressure of fluid from said source entering said inlet from a closed position disposed be tween said inlet and said'outlet closing said passageway to flow of said fluid therethrough to an open position past said outlet thereby placing said inlet and outlet in communication with each othen-andindicator means connected with said piston movable from a substantially concealed position to an exposed position when said piston is anoved tosaid open position and meansconnected with-said indicator means for'holding the latter to said body when said indicator means is in exposed position whereby said indicator means will be secured to said body and visible at all times when in said exposed position.

2. An indicating device adapted to provide part of a discharge conduit from a source of a fluid under pressure comprising: a body having a passageway therein, an inlet and an outlet opening into said passageway at spaced points therealong, a piston within said passageway movable therealong under the pressure of fluid from said source entering said inlet from a closed position disposed between said inlet and said outlet closing said passageway to flow of said fluid therethrough to an open position past said outlet thereby placing said inlet and outlet in communication with each other, and indicator means connected with said piston movable from a substantially concealed position to an exposed position when said piston is moved to said open position, a frangible seal securing said piston in said closed position and breakable under' the pressure of said fluid entering said inlet and causing said movement of said piston and said means, said piston frictionally engaging'said body for holding said piston stationary and for thereby holding indicator means in its exposed position when said piston is moved to its said exposed position.

3. An indicating device for indicating loss of CO gas from a container having liquid CO therein and which container is provided with a valved discharge conduit comprising: a body having a passageway therein, and an inlet communicating with one end of said passageway, means for securing said body to said conduit with said inlet in communication with the latter for admitting gas from said conduit into said one end of said p y,

an outlet in said body communicating with said passageway at a point spaced from said one end thereof, a piston in said passageway movable under pressure of gas entering said inlet from a closed position in which it is disposed between said inlet and said outlet, away from said inlet and across said outlet to an open position at the opposite end of said passageway from said inlet, a stem on said piston projecting from the side of the latte-r that is remote from said inlet, an opening formed in said body communicating between the outside of said body and said opposite end of said passageway, said stern projecting into said opening and substantially wholly disposed within the confines of the sides of said opening when said piston is in said closed position and movable through said opening to a position projecting outwardly from said body when said piston is in said open position and said piston including means in engagement with said body for holding said piston and said stem stationary when said piston is in said open position and when said stem is projecting outwardly from said body.

4. An indicating device for indicating loss of CO gas from a container having liquid CO therein and which container is provided with a valved discharge conduit comprising: a body having a passageway therein, and an inlet communicating with one end of said passageway, means for securing said body to said conduit with said inlet in communication with the latter for admitting gas from said conduit into said one end of said passageway, an outlet in said body communicating with said passageway at a point spaced from said one end thereof, a piston in said passageway movable under pressure of gas entering said inlet from a closed position in which it is disposed between said inlet and said outlet, away from said inlet and across said outlet to an open position at the opposite end of said passageway from said inlet, a stern on said piston projecting from the side of the latter that is remote from said inlet, an opening formed in said body communicating between the outside of said body and said opposite end of said passageway, said stem projecting into said opening and substantially wholly disposed within the confines of the sides of said opening when said piston is in said closed position and movable through said opening to a position projecting outwardly from said body when said piston is in said open position, the portion of said body having said opening therein comprising a head piece separable from the remainder of said body, means for removably securing said head piece to said remainder of said body, and the portion of said head piece defining the sides of said opening being engageable with said piston for holding said piston within said passageway when it is moved to said open position.

5. An indicating device for indicating loss of CO gas from a container having liquid CO therein and which container is provided with a valved discharge conduit comprising: a body having a passageway therein, and an inlet communicating with one end of said passageway, means for securing said body to said conduit with said inlet in communication with the latter for admitting gas from said conduit into said one end of said passageway, an outlet in said body communicating with said passageway at a point spaced from said one end thereof, a piston in said passageway movable under pressure of gas entering said inlet from a closed position in which it is disposed between said inlet and said outlet, away from said inlet and across said outlet to an open position at the opposite end of said passageway from said inlet, a stem on said piston projecting from the side of the latter that is remote from said inlet, an opening formed in said body communicating between the out side of said body and said opposite end of said passageway, said stem projecting into said opening when said piston is in said closed position and movable through said opening to a position projecting outwardly from said body when said piston is in said open position, the por tion of said body having said opening therein comprising a head piece separable from the remainder of said body, means for removably securing said head piece to said remainder of said body, and the portion of said head piece defining the sides of said opening being engageable with said piston for holding said piston Within said passageway when it is moved to said open position, means on said head piece accessible at all times from outside said head for removably securing a seal on said head piece in a visible position at'the outer side of said head extending across said opening and over the end of said stem when said piston is in said closed position, a frangible seal in said position secured to said means, said seal being breakable under the force of said stern thereagainst when said piston is moved to said open position under pressure of gas entering said inlet.

6. In combination with a container having a liquified gas therein that is vaporizable at atmospheric temperature and pressure comprising: a conduit communicating with the inside of said container at the upper end of the latter and extending outside said container, a valve interposed in said conduit outside said container movable from a closed position closing said conduit to fiow of gas therethrough to an open position opening said conduit to flow of gas through the latter and vice versa, said conduit including a body having a passageway therethrough communicating at one end with the portion of the conduit adapted to receive gas from said valve when the latter is moved to open position, duct in said body communicating with said passageway at a point spaced from said one end of said passageway for conducting as to outside said body, a piston in said passageway between said one end of the latter and said point movable in said passageway past said point under the pressure of gas adapted to flow in said conduit through and from said valve to provide for passage of gas entering said one end of said passageway through the latter and through said duct, and an indicator connected with said piston substantially enclosed by said body when said piston is between said one end of said passageway and said duct and movable with said piston to a position projecting a substantial distance outwardly of said body when said piston is moved past said duct in direction away from said one end of said passageway, and a seal on said body outside the latter engageable by said indicator for holding said indicator enclosed Within said body when said piston is between said one end of said passageway and said duct, said seal being breakable under the force of said indicator when said piston is moved past said duct under the influence of gas entering said one end of said passageway.

References Cited in the file of this patent UNITED STATES PATENTS 2,067,829 Denne Jan. 12, 1937 2,483,657 Messick Oct. 4, 1949 2,767,797 Allen Oct. 23, 1956 2,775,951 Billrneyer Jan. 1, 1957 

